Biosolids concentrator and digester system and method

ABSTRACT

Methods and systems of a biosolids concentrator and digester system having an inlet, an equalization/separation tank, an equalization/separation tank-anaerobic tank connector, an anaerobic tank, an anaerobic tank-aerobic tank connector, an aerobic tank, an aerobic tank-clarifier tank connector, and a clarifier tank. The inlet receives a thermally treated waste stream (TTWS), which enters the equalization/separation tank through the inlet at the equalization/separation tank bottom portion and leaves at the equalization/separation tank top portion. The TTWS enters the anaerobic tank at the anaerobic tank bottom portion and is anaerobically digested in the anaerobic tank producing a biogas, which is discharged from the anaerobic tank top portion. The TTWS leaves the anaerobic tank at the anaerobic top portion, enters the aerobic tank at the aerobic tank bottom portion and leaves the aerobic tank at the anaerobic top portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/248,754, filed Jan. 15, 2019, the disclosure of which ishereby incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISC APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

The present invention relates to biosolids concentrator and digestersystems and methods.

BRIEF SUMMARY OF THE INVENTION

In an embodiment of the present invention, a biosolids concentrator anddigester system comprises an inlet, a digester, a digester-firstclarifier connector, a first clarifier, a first clarifier-micron filterconnector, a micron filter, a micron filter-membrane filter connector, amembrane filter, and an outlet. The inlet receives a waste stream. Theinlet is in fluid communication with the digester. The digester is influid communication with the first clarifier through the digester-firstclarifier connector. The first clarifier is in fluid communication withthe micron filter through the first clarifier-micron filter connector.The micron filter is in fluid communication with the membrane filterthrough the micron filter-membrane filter connector. The membrane filteris in fluid communication with the outlet.

In another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a firstclarifier-first manifold connector, a micron filter-first manifoldconnector, a membrane filter-first manifold connector, a first manifold,a first manifold-sludge digester set connector, a sludge digester set, asludge digester set-second clarifier connector, a second clarifier, anda second clarifier-first clarifier connector. The first clarifier is influid communication with the first manifold through the firstclarifier-first manifold connector. The micron filter is in fluidcommunication with the first manifold through the micron filter-firstmanifold connector. The membrane filter is in fluid communication withthe first manifold through the membrane filter-first manifold connector.The first manifold is in fluid communication with the sludge digesterset through the first manifold-sludge digester set connector. The sludgedigester set is in fluid communication with the second clarifier throughthe sludge digester set-second clarifier connector. The second clarifieris in fluid communication with the first clarifier through the secondclarifier-first clarifier connector.

In yet another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a secondclarifier-mineral sludge tank connector and a mineral sludge tank. Thesecond clarifier is in fluid communication with the mineral sludge tankthrough the second clarifier-mineral sludge tank connector.

In another embodiment of the present invention, a component is thermallytreated. The component is selected from the group consisting of theinlet, the digester, the first manifold, the first manifold-sludgedigester set connector, the sludge digester set, and combinationsthereof.

In yet another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a membrane filter-pHadjustment/chlorination tank connector and a pH adjustment/chlorinationtank.

The membrane filter is in fluid communication with the pHadjustment/chlorination tank through the membrane filter-pHadjustment/chlorination tank connector. The pH adjustment/chlorinationtank is in fluid communication with the outlet.

In another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a firstclarifier-first manifold connector, a micron filter-first manifoldconnector, a membrane filter-first manifold connector, a first manifold,a first manifold-sludge digester set connector, a sludge digester set, asludge digester set-second clarifier connector, a second clarifier, anda second clarifier-first clarifier connector. The first clarifier is influid communication with the first manifold through the firstclarifier-first manifold connector. The micron filter is in fluidcommunication with the first manifold through the micron filter-firstmanifold connector. The membrane filter is in fluid communication withthe first manifold through the membrane filter-first manifold connector.The first manifold is in fluid communication with the sludge digesterset through the first manifold-sludge digester set connector. The sludgedigester set is in fluid communication with the second clarifier throughthe sludge digester set-second clarifier connector. The second clarifieris in fluid communication with the first clarifier through the secondclarifier-first clarifier connector.

In yet another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a secondclarifier-mineral sludge tank connector and a mineral sludge tank. Thesecond clarifier is in fluid communication with the mineral sludge tankthrough the second clarifier-mineral sludge tank connector.

In another embodiment of the present invention, a component is thermallytreated. The component is selected from the group consisting of theinlet, the digester, the first manifold, the first manifold-sludgedigester set connector, the sludge digester set, and combinationsthereof.

In yet another embodiment of the present invention, a biosolidsconcentrator and digester system comprises an inlet, anequalization/separation tank, an equalization/separation tank-anaerobictank connector, an anaerobic tank, an anaerobic tank-aerobic tankconnector, an aerobic tank, an aerobic tank-clarifier tank connector,and a clarifier tank. The inlet receives a waste stream. The inlet is influid communication with the equalization/separation tank. Theequalization/separation tank comprises an equalization/separation tanktop portion, an equalization/separation tank bottom portion, and a firstaeration tube. The anaerobic tank comprises an anaerobic tank topportion and an anaerobic tank bottom portion. The aerobic tank comprisesan aerobic tank top portion, an aerobic tank bottom portion, and asecond aeration tube. The equalization/separation tank is in fluidcommunication with the anaerobic tank through theequalization/separation tank-anaerobic tank connector. The waste streamenters the equalization/separation tank through the inlet at theequalization/separation tank bottom portion. The waste stream leaves theequalization/separation tank through the equalization/separationtank-anaerobic tank connector at the equalization/separation tank topportion. The anaerobic tank is in fluid communication with the aerobictank through the anaerobic tank-aerobic tank connector. The waste streamenters the anaerobic tank through the equalization/separationtank-anaerobic tank connector at the anaerobic tank bottom portion. Thewaste stream leaves the anaerobic tank through the anaerobictank-aerobic tank connector at the anaerobic top portion. The aerobictank is in fluid communication with the clarifier tank through theaerobic tank-clarifier tank connector. The waste stream enters theaerobic tank through the anaerobic tank-aerobic tank connector at theaerobic tank bottom portion. The waste stream leaves the aerobic tankthrough the aerobic tank-clarifier tank connector at the anaerobic topportion.

In another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises anequalization/separation tank-second manifold connector, an anaerobictank-second manifold connector, an aerobic tank-second manifoldconnector, a clarifier tank-second manifold connector, a secondmanifold, and a second manifold outlet. The equalization/separation tankis in fluid communication with the second manifold through theequalization/separation tank-second manifold connector. The anaerobictank is in fluid communication with the second manifold through theanaerobic tank-second manifold connector. The aerobic tank is in fluidcommunication with the second manifold through the aerobic tank-secondmanifold connector. The clarifier tank is in fluid communication withthe second manifold through the clarifier tank-second manifoldconnector. The second manifold is in fluid communication with the secondmanifold outlet.

In yet another embodiment of the present invention, a component isthermally treated. The component is selected from the group consistingof the inlet, the equalization/separation tank, theequalization/separation tank-anaerobic tank connector, the anaerobictank, the anaerobic tank-aerobic tank connector, the aerobic tank, andcombinations thereof.

In another embodiment of the present invention, a method ofconcentrating and digesting biosolids comprises processing a wastestream through a biosolids concentrator and digester system andestablishing fluid communications between the inlet, the digester, thefirst clarifier, the micron filter, and the membrane filter. Thebiosolids concentrator and digester system comprises a digester, a firstclarifier, a micron filter, and a membrane filter.

In yet another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a pHadjustment/chlorination tank. The method of concentrating and digestingbiosolids further comprises establishing fluid communication between themembrane filter and the pH adjustment/chlorination tank.

In another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a first manifold, asludge digester set, and a second clarifier. The method of concentratingand digesting biosolids further comprises establishing fluidcommunication between the first manifold, the micron filter, themembrane filter, the sludge digester set, the second clarifier, and thefirst clarifier.

In yet another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a mineral sludgetank. The method of concentrating and digesting biosolids furthercomprises establishing fluid communication between the second clarifierand the mineral sludge tank.

In another embodiment of the present invention, the method ofconcentrating and digesting biosolids further comprises thermallytreating a component. The component is selected from the groupconsisting of the digester, the first manifold, the sludge digester set,and combinations thereof.

In yet another embodiment of the present invention, a method ofconcentrating and digesting biosolids comprises processing a wastestream through a biosolids concentrator and digester system andestablishing fluid communications between the equalization/separationtank, the anaerobic tank, the aerobic tank, and the clarifier tank. Thebiosolids concentrator and digester system comprises anequalization/separation tank, an anaerobic tank, an aerobic tank, and aclarifier tank.

In another embodiment of the present invention, the biosolidsconcentrator and digester system further comprises a second manifold anda second manifold outlet. The method of concentrating and digestingbiosolids further comprises establishing fluid communication between theequalization/separation tank, the second manifold, the anaerobic tank,the aerobic tank, the clarifier tank and the second manifold outlet.

In yet another embodiment of the present invention, the method ofconcentrating and digesting biosolids further comprises thermallytreating a component. The component is selected from the groupconsisting of the equalization/separation tank, the anaerobic tank, theaerobic tank, and combinations thereof.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The advantages and features of the present invention will be betterunderstood as the following description is read in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a diagram of an embodiment of the present invention

FIG. 2 is a diagram of another embodiment of the present invention

For clarity purposes, all reference numerals may not be included inevery figure.

DETAILED DESCRIPTION OF THE INVENTION

The present invention can provide for the elimination of nearly 90% ofthe water in the waste stream and allows for a compact digester systemfor handling low Biochemical Oxygen Demand (BOD) concentration wastestreams. A process and apparatus for treatment are disclosed. ABio-Solids Concentrator and Digester System (BCDS) according to thepresent invention, uses tanks that are more compact than common tricklefilter to digest simple compounds in the waste stream rapidly. ABio-Solids Concentrator and Digester System (BCDS) according to thepresent invention uses air stratification to separate compounds withhigher density from compounds with lower density; and also usesclarification, micron filtration and membrane filtration to clean thewaste stream water to near drinking water quality for discharge. Thiseliminates all of the excess water so that the system for digesting thewaste can be smaller than a common trickle filter, for example onequarter the size of a common trickle filter. The bottom of the clarifierand the back flush from both the micron filter system and the membranefilter system can be sent to a second digester additional reduction inBOD (e.g., 85-90% reduction of BOD) providing for a substantialreduction in sludge production.

The present invention can be regulated for adaptable operation and isreliable. Operation could be maximum reduction of the waste stream orcould be utilized to provide for high volumes of methane production. Themicrobial environment is determined by the makeup of the waste streamand the environment in the digesters as the microbial ecology willadjust to the substrates that are available for use as food. This systemmimics natural environmental systems found in aqueous environments.

Tanks may preferably be insulated or enclosed in a climate-controlledbuilding to provide for a stable temperature regime especially ifanaerobic digestion is preferred. A stable temperature encourages astable microbial environment and will produce the best results forconsuming the waste stream. As the microbial community grows anddevelops it may eventually become too large for the tanks and mayrequire a mechanical sloughing to remove excess microbial biomass andencourage rapid growth of new biomass. Mechanical sloughing is preferredas it is controllable and allows for pruning of the microbial communitywhen it is most advantageous for consuming the waste stream.

The back-flush of the micron filter and the membrane filter that containresiduals of the microbial biomass is directed into a sludge digesterthat also receives periodically mechanically sloughed microbial biomass(e.g., from the digesters) that are separated from the waste stream inthe first clarifier. Mechanically sloughing the microbial biomass allowsfor the control of the infiltration rate of the bio filters in thedigesters and also encourages the rapid growth phase of the microbialbiomass that encourages the uptake of the simpler compounds in the wastestream.

By eliminating excess water from the waste stream and by concentratingthe bio-solids for digestion, a system according to this inventionprovides for maximum digestion of the bio-solids in a much smallersystem than that of a common system using for example trickle filters

By way of example a 40,000 gal/day (gallons per day) system at 300 mg/L(milligrams per liter) BOD has only 150 lbs/d (pounds per day) of actualbiologically degradable solids. A system according to this invention todigest this 150 lbs/day of bio-degradable solids can comprise four6,000-gallon tanks or 24,000 gal/day total volume as compared to 160,000gal/d total volume for a common trickle filter.

The process according to an embodiment of this invention is a biologicalprocess utilizing a series of bio filters to eliminate biodegradablecompounds in waste streams and provide for the production of aconcentrated sludge that can be settled easily in a clarifier, prior tomechanical separation and filtration of the waste stream. Such stepsallow for the elimination of the majority of the waste water andguarantee the quality of the discharge while retaining the biodegradableorganic compounds for complete degradation in a sludge digester. Theelimination of the excess waste water eliminates the necessity to useextremely large size bio filters required to handle the entire wastewater stream as is done in a common trickle filter system.

FIG. 1 shows an embodiment of the present invention that is capable oftaking low Biochemical Oxygen Demand (BOD) waste streams that havemostly soluble compounds that are not easily separated but are easilydigested and convert the low BOD waste streams into microbial biomassthat can be easily separated in a common clarification system.

For example, as illustrated in FIG. 1, low BOD waste stream (e.g., BODof 300 mg/L or less) containing soluble compounds that are not easilyseparated from the waste stream water enters a first digester set 1through inlet pipe 20. The first digester set 1 may comprise one or morebio-filters that digest (e.g., break down) biodegradable materials usingmicroorganisms. The soluble compounds in the waste stream are digestedin the first digester set 1 and converted to microbial biomass which isheavier than the waste stream water. A portion of the microbial biomasswill settle in the first digester set 1 while another portion of themicrobial biomass will flow with the waste stream through connector pipe9 from the first digester set 1 into the first clarifier 2. In the firstclarifier 2 the microbial biomass derived in the first digester set 1from the soluble compounds can now readily be separated, for example bysedimentation, and removed from the waste stream. From the firstclarifier 2 the waste stream, now with the microbial biomass removed, istransferred through pipe connector 10 into the micron filter 3 where thewaste stream water is further removed of BOD by removing organicparticles with sizes larger than the rating of the micron filter 3. Themicron filter 3 may comprise one or more micron screens arranged inseries, each with filter openings, for example in the range of 0.22 to 5microns, or even smaller in some situations. The filtered waste streamwater exits the micron filter 3 through pipe connector 11 and enters themembrane filter 4 where the BOD is still further reduced by filteringparticles larger than the rating of the membrane filter 4. The membranefilter 4 may comprise one or more semi-permeable membranes capable offiltering particles smaller than the particles filtered by the micronfilter 3, for example in the range of 0.001-1 micron. The waste streamwater filtered through the membrane filter 4 has very low BOD (forexample, in the range of 5 to 10 mg/L; this range however, could varysubstantially depending on the content of the waste stream) and exitsthe membrane filter 4 through pipe 12 from where it may be transportedto a pH adjustment/chlorination tank 5 and then is discharged as neardrinking water quality through outlet pipe 13. In this embodiment pHadjustment/chlorination tank 5 may be a pH adjustment tank, achlorination tank, or a combination of a pH adjustment tank and achlorination tank. In the alternative the waste stream water exiting themembrane filter 4 through pipe 12 may be discharged in the environment(not shown) without passing through the pH-adjustment/chlorination tank5.

The portion of the microbial biomass that settles in the first digesterset 1, as described above, may be periodically mechanically sloughed sothat it can flow with the waste water stream water through pipe 9 intothe first clarifier 2 for separation. The period of mechanical sloughingcan be determined by the rate at which the microbial biomass settles inthe first digester set 1, and can range for example from under 20minutes to 2 days, or even more in some circumstances.

The solids separated from the waste stream in the first clarifier 2, canbe directed to the sludge digester set (6) through pipe connector 14.The back flush from the micron filter 3 is directed to the sludgedigester set 6 through pipe connector 17, and the back flush from themembrane filter 4 is directed to the sludge digester set 6 through pipeconnector 16. The sludge digester set 6 may comprise one or morebio-filters that can be arranged in series to microbiologically degradethe organic component of the sludge into carbon dioxide and water(“sludge water”). With embodiments of this invention it is possible tomicrobiologically degrade 80%-90% and even more, of the sludge andconvert it into carbon dioxide and sludge water. The sludge water exitsthe sludge digester set 6 through pipe connector 15 and enters thesecond clarifier 7 where any remaining mineral solids are settled andseparated from the water resulting in clean sludge water. The cleansludge water from the second clarifier 7 leaves through pipe connector19 and is directed back into the first clarifier 2 and subsequentlythrough pipe connector 10 to the micron filter 3, and through pipeconnector 11 to the membrane filter 4, from where it may be transportedthrough pipe 12 to the pH adjustment/chlorination tank 5, andsubsequently discharged through outlet pipe 13 as near drinking waterquality. In the alternative the pipe connecter 12 may not feed into a pHadjustment/chlorination tank 5, and instead discharge into theenvironment or another container (not shown).

The solids separated from the sludge water in the second clarifier 7leave through the through pipe connector 18 and are transferred to themineral sludge tank 8 for disposal.

FIG. 2 illustrates another embodiment of the present invention capableof handling waste streams with high levels of BOD, reaching as high asBOD of 20,000, or more, which may be generated as industrial waste, forexample in the food and beverage Industry. For example, liquid wastecontaining sludge is transported as a waste stream through input pipe105 into the equalization/separation tank 101 through the input pipe105. In the equalization/separation tank 101 the heavy components of thewaste stream, such as sand, silt, clay, and/or others, are separatedfrom the medium and light components, for example organic componentswith lower density. For convenience in this description we use the term“heavy” to refer to waste stream components with, for example, 2.65 orhigher Specific Gravity relative to Water (SG measured in grams percubic centimeter (g/cm3 or g/cc)) and the term “light” to refer to wastestream components with less than 1.4 SG. Waste stream components between1.4 SG and 2.65 SG will, for convenience be referred to as “medium.” Theequalization/separation tank 101 also may equalize the downstream flow,thereby reducing fluctuation and facilitating the light and medium wastestream components' flow to the subsequent tanks. It will be understoodthat the “heavy,” “medium” and “light” ranges provided for thisembodiment are solely examples and are non-limiting. Any separation ofwaste stream components resulting from the components' differentspecific gravities or densities will satisfy this invention.

Input pipe 105 may direct the waste stream towards the bottom of theequalization/separation tank 101. Air may be introduced near the bottomof equalization/separation tank 101 at a rate selected by an operatorthrough aerator 106. The air flows from aerator 106 into theequalization/separation tank 101 and travels upwards taking with it thelight and medium particulate components of the waste stream that isbeing directed downward by input pipe 105. In some embodiments inputpipe 105 may release the waste stream near the bottom of theequalization/separation tank 101 instead of just directing it downward.Such a configuration in which both the waste stream and the air areintroduced near the bottom of equalization/separation tank 101 isbeneficial for very high BOD waste streams as it may prevent or reducethe air and/or oxygen depletion in the equalization/separation tank 101.Oxygen and/or air depletion may result when high BOD waste stream is fednear the top of the equalization/separation tank 101 and air isintroduced near the bottom and the oxygen is depleted as air travelsupwards. When the air reaches the waste stream with highest BOD it maybe depleted of oxygen, which in turn may cause the aerobic microbialcommunity in the equalization/separation tank 101 to collapse. In thisembodiment of the invention, introducing both the air and the high BODwaste stream at or near the bottom of the equalization/separation tank101 ensures that the maximum oxygen content of the air coincides withthe maximum BOD of the waste stream reducing the risk of oxygendepletion.

As the waste stream components are separated based on the components'varying specific gravity or density the heavy components stay closer to,and accumulate near the bottom of the equalization/separation tank 101and the light components are taken up with the rising air. The organicheavy components of the waste stream that collect near the bottom of theequalization/separation tank 101 degrade through aerobic and/oranaerobic microbial activity into light and medium components, which areeventually raised upwards with the air through theequalization/separation tank 101. As the light and medium components aredirected toward the top of the equalization/separation tank 101 theyeventually exit the equalization/separation tank 101 together with thewaste stream through connector pipe 107. Connector pipe 107 may directthe waste stream carrying the light and medium components downward intothe anaerobic tank 102, or pipe 107 may extend downward into anaerobictank 102 and releases the waste stream carrying the light and mediumcomponents near the bottom of the anaerobic tank 102. In the anaerobictank 102 anaerobic bacteria degrades, or converts the organic componentsof the waste stream into simple sugars, fatty acids (e.g., formic acid,acetic acid, and other carboxylic acids) and other simple compounds,which travel upwards through the anaerobic tank 102. Biogas (e.g.,methane, carbon dioxide) from the anaerobic degradation of the organiccomponents may be collected from anaerobic tank 102 for further use(e.g., methane for fuel, after separation from CO2) or other processing(e.g., external gas system). A gas outlet 102 a may be added toanaerobic tank 102 to facilitate collection of biogases.

As the simple sugars, fatty acids, other simple compounds reach the topof the anaerobic tank 102 they exit through connector pipe 108 andtravel to the aerobic digester 103 where they may enter at the bottom ofthe aerobic digester 103 and travel upwards. Anaerobically digesting thewaste stream compounds in the anaerobic tank 102 prior to the aerobicdigester 103 facilitates the larger complex compounds' break down to thesimple compounds (e.g., simple sugars, fatty acids and other simplecompounds) without air which are then transferred into the aerobicdigester 103 where they are easier to digest than the original largercomplex compounds, such as cellulose, and others. Waste streams rich incellulose or other organic compounds can be utilized for high volumes ofbiogas production.

Air may be introduced near the bottom of the aerobic digester 103 at arate selected by an operator through aerator 109. The air flows fromaerator 109 and travels upwards taking up with it the fatty acids andsimple sugars. As the simple sugars and fatty acids move up through theaerobic digester 103 they are digested into carbon dioxide and water andexit the aerobic digester 103 through pipe 110 and enter the clarifiertank 104, from where they are discharged through pipe 111.

Mineral components of the waste stream tend to settle at the bottom ofthe tanks 101, 102, 103, 104. These mineral components can be removedthrough pipes 112, 113, 114, 115 and exit through manifold 116 to thedischarge pipe 117.

The Bio-solids Concentrator and Digester System provides a system andprocess where a waste stream is passed through a series of fixed filmanaerobic or aerobic digesters where larger solids become trapped in thefixed film membrane along with the ecological components of themicrobial community. This configuration provides for the utilization anduptake of simple organic compounds in the waste stream that otherwisewill be difficult or impossible to be separated from the waste streamand their associated conversion into microbial biomass. This microbialbiomass is heavier than the waste stream with dissolved simple organiccompounds and therefore settles much more rapidly than does the simplerorganic compounds that make up most of the dissolved solids present inthe original waste stream. The output of the digesters is transferred toa clarifier where this heavier microbial biomass are settled out, andthe clarified waste stream is then transferred from a clarifier to asequence of one or more filters, including micron filters and membranefilters. The waste stream clarified from the filters is discharged fromthe membrane filter to the environment at near drinking water quality.

An embodiment of a system according to this invention can also utilize athermal treatment of the microbial biomass to break it down into simplercompounds for more rapid digestion in either an aerobic or an anaerobicdigester. Thermal treatment, for example through heating, may be appliedto any of the tanks where aerobic or anaerobic degradation occurs,preferably to one or more of the first digester set 1, sludge digester6, equalization/separation tank 101, anaerobic tank 102, aerobicdigester 103, or to one or more of the connectors feeding those tanks ordigesters, for example inlet pipe 20, pipe connectors 14, 16, 17, inputpipe 105, connector pipes 107, 108. In embodiments in which thermallytreated or heated waste stream enters through input pipe 105, and/or inwhich the equalization/separation tank 101 is thermally treated byapplying heat, the waste stream entering anaerobic tank 102 throughconnector pipe 107 may introduce heat energy to tank 102 to facilitatethermal treatment of the waste stream in anaerobic tank 102 byincreasing the temperature of anaerobic tank 102 and/or by helpingmaintain stable temperature. Such embodiments may increase theefficiency of anaerobic digester 102 by, for example, reducing or eveneliminating the need for an external heat source.

Thermally treated waste streams rich in cellulose, grease, oils andother similar organic compounds may contain high concentrations of fattyacids, which are “light” (e.g., SG less than 1.4), and will be directedtoward the top of the equalization/separation tank 101 and exit theequalization/separation tank 101 together with the waste stream throughconnector pipe 107 where they can be extracted using well known methods.For example, the waste stream exiting tank 101 may be mixed (e.g., witha mixer) with non-polar solvent (e.g., hexane, propane or othernon-polar solvent), which will associate with the fatty acids present inthe waste stream resulting in a fatty acid non-polar solution. Thesolution, having specific gravity lower than the waste stream will raiseto the top of the waste stream and may be extracted after it separateson top of the waste stream. The solvent may be mixed with the wastestream in connector pipe 107, and the resulting solution may beextracted from connector pipe 107 prior to aerobic tank 102 using aninline fluid extractor. Alternatively, a fatty-acids separation tank(not shown) to receive and mix the solvent with the waste stream may beprovided in-line with pipe connector 107, between anaerobic tank 101 andaerobic tank 102. A PH adjustment towards acid may also be implementedwhen mixing the solvent and waste stream to encourage the separation ofthe fatty acids into the non-polar phase.

A process according to this invention does not require a particularstart up method other than to begin the flow of the waste stream intothe bio filters, which starts the growth of microbes that are mostsuited to digest the introduced waste stream. Running the tanks at ahigh BOD level with respect to the membrane media provides for rapidgrowth and development of the microbial biomass. There are norequirements to raise or lower the BOD levels of the bio filters as thisprovides no advantage to the growth of the microbial biomass. If themicrobial biomass needs to be reduced to increase infiltration rates inthe bio filters, it can be done mechanically either at timed intervalsor by measuring the amount of pore space available in the bio filter.This is done by comparison of the amount of pore space in the bio filterwith membrane installed prior to any microbial biomass growth, asdetermined by measuring the amount of water to fill the reactor andcomparison with the amount of water when bio filter is full of microbialbiomass.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes, omissions, and/or additions may be made and equivalentsmay be substituted for elements thereof without departing from thespirit and scope of the invention. In addition, many modifications maybe made to adapt a particular situation or material to the teachings ofthe invention without departing from the scope thereof. Therefore, it isintended that the invention not be limited to the particular embodimentsdisclosed as the best mode contemplated for carrying out this invention,but that the invention will include all embodiments falling within thescope of the appended claims. Moreover, unless specifically stated anyuse of the terms first, second, etc. do not denote any order orimportance, but rather the terms first, second, etc. are used todistinguish one element from another.

I claim:
 1. A biosolids concentrator and digester system comprises: aninlet; an equalization/separation tank; an equalization/separationtank-anaerobic tank connector; an anaerobic tank; an anaerobictank-aerobic tank connector; an aerobic tank; an aerobic tank-clarifiertank connector; and, a clarifier tank; wherein the inlet receives athermally treated waste stream; wherein the inlet is in fluidcommunication with the equalization/separation tank; wherein theequalization/separation tank comprises: an equalization/separation tanktop portion; an equalization/separation tank bottom portion; and, afirst aeration tube; wherein the anaerobic tank comprises: an anaerobictank top portion; and, an anaerobic tank bottom portion; wherein theaerobic tank comprises: an aerobic tank top portion; an aerobic tankbottom portion; and, a second aeration tube; wherein theequalization/separation tank is in fluid communication with theanaerobic tank through the equalization/separation tank-anaerobic tankconnector; wherein the thermally treated waste stream enters theequalization/separation tank through the inlet at theequalization/separation tank bottom portion; wherein the thermallytreated waste stream leaves the equalization/separation tank through theequalization/separation tank-anaerobic tank connector at theequalization/separation tank top portion; wherein the anaerobic tank isin fluid communication with the aerobic tank through the anaerobictank-aerobic tank connector; wherein the thermally treated waste streamenters the anaerobic tank through the equalization/separationtank-anaerobic tank connector at the anaerobic tank bottom portion;wherein the thermally treated waste stream is anaerobically digested inthe anaerobic tank producing a biogas; wherein the biogas is dischargedfrom the anaerobic tank top portion; wherein the thermally treated wastestream leaves the anaerobic tank through the anaerobic tank-aerobic tankconnector at the anaerobic top portion; wherein the aerobic tank is influid communication with the clarifier tank through the aerobictank-clarifier tank connector; wherein the thermally treated wastestream enters the aerobic tank through the anaerobic tank-aerobic tankconnector at the aerobic tank bottom portion; wherein the thermallytreated waste stream leaves the aerobic tank through the aerobictank-clarifier tank connector at the anaerobic top portion.
 2. Thebiosolids concentrator and digester system of claim 1, wherein theanaerobic tank top portion comprises a gas outlet; and wherein thebiogas is discharged from the gas outlet.
 3. The biosolids concentratorand digester system of claim 1, wherein the anaerobic tank is thermallytreated; and, wherein the thermally treated waste stream provides heatenergy to the anaerobic tank to thermally treat the anaerobic tank. 4.The biosolids concentrator and digester system of claim 3 furthercomprising: an equalization/separation tank-second manifold connector;an anaerobic tank-second manifold connector; an aerobic tank-secondmanifold connector; a clarifier tank-second manifold connector; a secondmanifold; and, a second manifold outlet; wherein theequalization/separation tank is in fluid communication with the secondmanifold through the equalization/separation tank-second manifoldconnector; wherein the anaerobic tank is in fluid communication with thesecond manifold through the anaerobic tank-second manifold connector;wherein the aerobic tank is in fluid communication with the secondmanifold through the aerobic tank-second manifold connector; wherein theclarifier tank is in fluid communication with the second manifoldthrough the clarifier tank-second manifold connector, and, wherein thesecond manifold is in fluid communication with the second manifoldoutlet.
 5. The biosolids concentrator and digester system of claim 1,wherein the thermally treated waste stream comprises fatty acids;wherein the biosolids concentrator and digester system performs a methodfor separating the fatty acids from the thermally treated waste stream,the method comprising: mixing the thermally treated waste stream withnon-polar solvent; and, forming a fatty acid non-polar solution; and,wherein the fatty acid non-polar solution separates on top of thethermally treated waste stream.
 6. The biosolids concentrator anddigester system of claim 5, wherein the anaerobic tank is thermallytreated; and, wherein the thermally treated waste stream provides heatenergy to the anaerobic tank to thermally treat the anaerobic tank. 7.The biosolids concentrator and digester system of claim 6 furthercomprising: an equalization/separation tank-second manifold connector;an anaerobic tank-second manifold connector; an aerobic tank-secondmanifold connector; a clarifier tank-second manifold connector; a secondmanifold; and, a second manifold outlet; wherein theequalization/separation tank is in fluid communication with the secondmanifold through the equalization/separation tank-second manifoldconnector; wherein the anaerobic tank is in fluid communication with thesecond manifold through the anaerobic tank-second manifold connector;wherein the aerobic tank is in fluid communication with the secondmanifold through the aerobic tank-second manifold connector; wherein theclarifier tank is in fluid communication with the second manifoldthrough the clarifier tank-second manifold connector, and, wherein thesecond manifold is in fluid communication with the second manifoldoutlet.
 8. A method of concentrating and digesting biosolids comprising:processing a thermally treated waste stream through a biosolidsconcentrator and digester system wherein the biosolids concentrator anddigester system comprises: an equalization/separation tank having anequalization/separation tank top portion and an equalization/separationtank bottom portion; an anaerobic tank having an anaerobic tank topportion and an anaerobic tank bottom portion; an aerobic tank having anaerobic tank top portion and an aerobic tank bottom portion; and, aclarifier tank; establishing fluid communications between theequalization/separation tank, the anaerobic tank, the aerobic tank, andthe clarifier tank; producing a biogas by anaerobically digesting thethermally treated waste stream in the anaerobic tank; and, collectingthe biogas from the anaerobic tank top portion; and, wherein thethermally treated waste stream enters the equalization/separation tankthrough an inlet at the equalization/separation tank bottom portion. 9.The method of concentrating and digesting biosolids of claim 8, whereinthe biosolids concentrator and digester system further comprises: asecond manifold; and, a second manifold outlet; wherein the method ofconcentrating and digesting biosolids further comprises: establishingfluid communication between the equalization/separation tank, the secondmanifold, the anaerobic tank, the aerobic tank, the clarifier tank andthe second manifold outlet.
 10. The method of concentrating anddigesting biosolids of claim 8 further comprising: thermally treatingthe anaerobic tank; and, transferring heat energy from the thermallytreated waste stream to the anaerobic tank.
 11. The method ofconcentrating and digesting biosolids of claim 8 wherein the thermallytreated waste stream comprises fatty acids; and, wherein the methodfurther comprises: mixing the thermally treated waste stream withnon-polar solvent to form a fatty acid non-polar solution; and,separating the fatty acid non-polar solution from the thermally treatedwaste stream.
 12. The method of concentrating and digesting biosolids ofclaim 11, wherein the biosolids concentrator and digester system furthercomprises: a second manifold; and, a second manifold outlet; wherein themethod of concentrating and digesting biosolids further comprises:establishing fluid communication between the equalization/separationtank, the second manifold, the anaerobic tank, the aerobic tank, theclarifier tank and the second manifold outlet.
 13. The method ofconcentrating and digesting biosolids of claim 11 further comprising:thermally treating the anaerobic tank; and, transferring heat energyfrom the thermally treated waste stream to the anaerobic tank.
 14. Abiosolids concentrator and digester system comprises: an inlet; anequalization/separation tank; an equalization/separation tank-anaerobictank connector; an anaerobic tank; an anaerobic tank-aerobic tankconnector; an aerobic tank; an aerobic tank-clarifier tank connector;and, a clarifier tank; wherein the inlet receives a thermally treatedwaste stream comprising fatty acids; wherein the inlet is in fluidcommunication with the equalization/separation tank; wherein theequalization/separation tank comprises: an equalization/separation tanktop portion; an equalization/separation tank bottom portion; and, afirst aeration tube; wherein the anaerobic tank comprises: an anaerobictank top portion; and, an anaerobic tank bottom portion; wherein theaerobic tank comprises: an aerobic tank top portion; an aerobic tankbottom portion; and, a second aeration tube; wherein theequalization/separation tank is in fluid communication with theanaerobic tank through the equalization/separation tank-anaerobic tankconnector; wherein the thermally treated waste stream enters theequalization/separation tank through the inlet at theequalization/separation tank bottom portion; wherein the thermallytreated waste stream leaves the equalization/separation tank through theequalization/separation tank-anaerobic tank connector at theequalization/separation tank top portion; wherein the anaerobic tank isin fluid communication with the aerobic tank through the anaerobictank-aerobic tank connector; wherein the thermally treated waste streamenters the anaerobic tank through the equalization/separationtank-anaerobic tank connector at the anaerobic tank bottom portion;wherein the thermally treated waste stream leaves the anaerobic tankthrough the anaerobic tank-aerobic tank connector at the anaerobic topportion; wherein the aerobic tank is in fluid communication with theclarifier tank through the aerobic tank-clarifier tank connector;wherein the thermally treated waste stream enters the aerobic tankthrough the anaerobic tank-aerobic tank connector at the aerobic tankbottom portion; wherein the thermally treated waste stream leaves theaerobic tank through the aerobic tank-clarifier tank connector at theanaerobic top portion; wherein the biosolids concentrator and digestersystem performs a method for separating the fatty acids from thethermally treated waste stream, the method comprising: mixing thethermally treated waste stream with a non-polar solvent; and, forming afatty acid non-polar solution; wherein the fatty acid non-polar solutionseparates on top of the thermally treated waste stream.
 15. Thebiosolids concentrator and digester system of claim 14, wherein theanaerobic tank is thermally treated; and, wherein the thermally treatedwaste stream transfers heat energy to the anaerobic tank.
 16. A methodof concentrating and digesting biosolids comprising: processing athermally treated waste stream through a biosolids concentrator anddigester system, wherein the thermally treated waste stream comprisesfatty acids, and wherein the biosolids concentrator and digester systemcomprises: an equalization/separation tank having anequalization/separation tank top portion and an equalization/separationtank bottom portion; an anaerobic tank having an anaerobic tank topportion and an anaerobic tank bottom portion; an aerobic tank having anaerobic tank top portion and an aerobic tank bottom portion; and, aclarifier tank; establishing fluid communications between theequalization/separation tank, the anaerobic tank, the aerobic tank, andthe clarifier tank; mixing the thermally treated waste stream withnon-polar solvent to form a fatty acid non-polar solution; and,separating the fatty acid non-polar solution on top of the thermallytreated waste stream; and, wherein the thermally treated waste streamenters the equalization/separation tank through an inlet at theequalization/separation tank bottom portion.
 17. The method ofconcentrating and digesting biosolids of claim 16 further comprising:thermally treating the anaerobic tank by transferring heat energy fromthe thermally treated waste stream to the anaerobic tank.